Quick answer: insulin resistance often has no clear symptoms. The signs that do show up include extra weight around the waist, darker velvety skin on the neck or armpits, skin tags, tiredness after meals, strong cravings, and blood tests showing high triglycerides or rising blood sugar. It can often be improved with lifestyle changes.
What insulin resistance is
Insulin is a hormone that helps your cells take sugar out of the blood. In insulin resistance, cells respond poorly, so the pancreas makes more insulin to compensate. For years, this can keep blood sugar normal while insulin stays high. Eventually the pancreas can’t keep up, and prediabetes or type 2 diabetes develops.
Physical signs
- Waist size above the healthy range. For many people that means over 40 inches (102 cm) for men and over 35 inches (88 cm) for women. Lower cutoffs are used for people of South Asian background.
- Darkened, velvety skin on the back of the neck, armpits, groin or knuckles (acanthosis nigricans)
- Skin tags, especially on the neck and armpits
- Irregular periods or signs of PCOS, such as acne and excess facial hair
- Fatigue, often after eating
Symptoms people notice
- Strong sugar and carb cravings
- Feeling hungry soon after meals
- Difficulty losing weight despite effort
- Trouble concentrating, sometimes called brain fog
These are not specific to insulin resistance, so the next step is testing, not guessing.
Blood test clues
- High triglycerides (150 mg/dL or higher) with low HDL cholesterol (below 40 mg/dL in men or 50 in women)
- Fasting glucose of 100 to 125 mg/dL, which falls in the prediabetes range
- A1C of 5.7% to 6.4%
- High blood pressure (130/80 or above)
- Raised liver enzymes or fat on a liver scan
Doctors usually diagnose from these results rather than from a single “insulin resistance test.” A fasting insulin level or a calculation called HOMA-IR is sometimes used, mostly in research or specialist settings.
Why it matters
Insulin resistance raises the risk of type 2 diabetes, fatty liver disease, high blood pressure, heart disease and PCOS-related problems. It often appears together with high triglycerides and belly fat, a cluster called metabolic syndrome. If your blood sugar is already a little high, read our guide to the signs of prediabetes.
What improves insulin sensitivity
Move your muscles. Walking after meals and strength training two days a week make muscles absorb sugar more effectively, even before you lose weight.
Lose weight if you carry extra. Losing 5 to 7% of body weight can improve insulin sensitivity.
Change what you eat. Cut sugary drinks and refined carbs, and eat more vegetables, beans, whole grains, fish and nuts.
Sleep and manage stress. Poor sleep and chronic stress both worsen insulin resistance.
Quit smoking and limit alcohol.
Medication when needed. Doctors may prescribe metformin or other treatments to some people, especially those with prediabetes at high risk, PCOS or a history of gestational diabetes.
When to see a doctor
If you have several of these signs or risk factors, such as family history of diabetes, PCOS or a history of gestational diabetes, ask for a fasting glucose, A1C and lipid panel. Early detection gives you the best chance of preventing diabetes.
Frequently asked questions
Can insulin resistance be reversed?
In many people it improves a lot with exercise, weight loss and diet changes, and blood sugar can return to normal.
Can slim people have insulin resistance?
Yes. Genetics, body fat distribution, inactivity and certain ethnic backgrounds raise the risk at lower weights.
Do I need an insulin test?
Not usually. Glucose, A1C and cholesterol results are more practical for most people.
Cura Editorial Team
Contributor at Cura Health Journal.